No problem!  

If you can't access it elsewhere, the thread is here:http://ireland.activeboard.com/t64057814/7-days-shannon-to-shannon-1118-25-first-visit/ 

A brief correction:  Doolin, the Burren and the Cliffs are actually South (and West) of Galway.

I realize that you've already pared down your wish list some, but I'm afraid you still need to cut back even more.  Seven days just doesn't allow for such a wide-spread a list.

As to the rest -- here's a couple of things:  1)  Why spend three days in/around Clare?  Day 2, Thursday night and Friday night?  With only 7 nights, that really plays havoc with your plans.  2) Your new plan has too many days to work well:  1 night Galway (Sat) + 2 nights Dublin (Sun, Mon)+1 night Kilkenny (Tues) + 2 nights Killarney (Weds, Thurs) + 1 night at "X" (Friday).  If your companions need to depart SNN at 1 PM on Thursday, Kilkenny needs to go.  SNN just too inconveniently far from Killarney to allow you to drive up, drop them off and then return to Killarney for the night.  Plus, it would 'short' them (and you) on time in County Clare.

Here's another option:  Don't rent a car in Shannon at all. Take the 9:30 AM bus, just as your companions plan.   Spend night 1 (Sat night) in Galway and then the four of you can take the train (or an Express Bus) into Dublin, where having a car is an expensive detriment.  Parking is difficult and expensive and you won't want, need or use the car while in the city.  That's Sun and Monday night.  Tuesday morning, rent the car in Dublin (there are depots along the South Circular road or at the airport) and drive to Killarney, for Night 4 and 5 (Tuesday and Wednesday) .  Alternately, take the train to Killarney and THEN rent the car.  On the morning of Day 6 (Thursday), drop your companions at the airport and drive to Bunratty.  Friday, visit the Cliffs and spend the night in Ennis. If your companions MUST see the Burren and the Cliffs, then you'll need to drop one night from Dublin.  If you drop to a single night in Killarney, I wouldn't bother going there at all, as you would most of the day just getting there and would basically only have an evening in town.

Train info:  http://www.irishrail.ie/fares-and-tickets/fares-info

Buying on line, in advance nets Large cost savings.

OK.  A Friday departure for your companions puts the Cliffs and Burren back into play for them -- but still requires giving up Kilkenny.  If you want to add a second night to Galway, then it will need to be subtracted from Dublin -- see my opinion about needing two nights in Killarney, in order to see much of anything in that area.

The only modification to my second plan ("On the morning of Day 6 (Thursday), drop your companions at the airport and drive to Bunratty.  Friday, visit the Cliffs and spend the night in Ennis."  would be this:  On the morning of Day 6 (Thursday) drive via the Cliffs and Burren to either Ennis or Bunratty.

There are numerous trains throughout the day that run between Galway and Dublin (and, Dublin to Killarney, if THAT appeals) so you could work a bit of a compromise -- Depart Galway in the early morning to spend more time in Dublin, or late afternoon / evening, to add time to Galway and reduce time in Dublin.  If driving to Killarney, I suggest leaving fairly early.  If taking the train, you have varying departure times to choose from.

For your 'Special' Friday night, a pricey option would be Dromoland Castle, which is a place US Presidents (and other dignitaries) have often stayed.      https://www.dromoland.ie/

If you want someplace a bit more 'Budget Friendly', either the Old Ground or Temple Gate, in Ennis, might suit.  Neither are as 'Posh' as Dromoland -- but they are also substantially less expensive!   

http://www.flynnhotels.com/Old_Ground_Hotel_Ennis/

http://www.templegatehotel.com/